Question
A URL shortener has 1000 redirects for every 1 new short URL creation. What is the most important design implication?
A
Optimize the read path and add caching
B
Optimize the write path 1000 times more than the read path
C
Use the database only as an append-only log
D
Avoid caching because URLs rarely change
Explanation
The system is read-heavy, so redirect path optimization and caching become critical.
URL shorteners are usually heavily skewed toward reads because users click existing short links far more often than they create new ones. This means the redirect path must be extremely fast and scalable. Caching popular short_code to long_url mappings, indexing the short_code column, and scaling read services are more important than over-optimizing writes early.